A type of gullet cancer (oesophageal adenocarcinoma) has become the 5th commonest UK cause of cancer death. Unfortunately, by the time patients have symptoms, the cancer is often incurable. People with Barrett's oesophagus (change of gullet lining occurring in some with acid reflux) at risk of this cancer can have regular check-ups, involving examination through an endoscope (an instrument inserted by mouth, under mild sedation if required). A small proportion of people with Barrett's develop further changes (which might become cancer) in the gullet lining; if they do, it is important to remove the affected tissue before cancer develops, or when it is at an early stage.